1. Field of the Invention
The present invention relates to image processing used in virtual stereo acoustics, and more particularly, to a method and apparatus for tracking the position of the head of a listener for virtual acoustics.
2. Description of Related Art
In virtual stereo acoustics, a listener can enjoy the best stereo sound effect when he/she is positioned in a so-called listening sweet spot, that is, an optimum listening area, predefined by a crosstalk cancellation processing. Outside of the listening sweet spot, the stereo sound effect is degraded. That is, the performance of a stereo sound system is sensitive to the relative positions of the listener and the listening sweet spot. Accordingly, it is desirable to maximize the size of (i.e. broaden) the listening sweet spot. However, maximizing the listening sweet spot by using known filtering technology is limited. As a result, other approaches are being explored. One such approach is resetting the location of the sweet spot based on a location of a listener. In order to perfectly reset the listening sweet spot with respect to the 3-dimensional (3D) movement of the listener, tracking of a 3D path of the listener's movement is essential. For this, conventional methods employ a magnetic, infrared or laser unit. However, these approaches result in increased user inconvenience.
Visual tracking is a major subject in the field of computer vision. Visual tracking is of such interest because it has become a factor lowering the cost of computing, video cameras and memories. In an image sequence taken around a video rate, a change between frames is not sudden, and this redundancy of information in relation to multiple images can be of great help in analyzing an input in order to track individual objects. An ideal algorithm for this application should be robust against background noise, capable of tracking the position of the head and efficient in calculation.